I've taken the ACT 3 times, and I've gotten the same composite score (28) every. single. time. It only goes up to a 29 even with superscoring, and I really would like to score above a 30. Will I look bad to colleges if I take the test a fourth time?
I wouldn't recommend taking the ACT a fourth time, mainly because of the consistency of your past three scores. Since your scores haven't improved over the course of the last few test administrations, it seems unlikely that you'll be able to raise them on your fourth try.
I would only advise you to take the test a fourth time if you're in the process of switching to an entirely new prep program and you have evidence that it's working better than your previous study methods. If you can improve your score to above a 30 on a consistent basis (at least three practice tests in a row), then it's reasonable to try taking the ACT a fourth time.
The main issue with retaking the test more than three times is not that colleges will judge you - it's that excessive testing can be a huge waste of your time and financial resources. Don't retake the test unless you feel completely confident that you can improve your scores.